Signal chain with embedded power management

ABSTRACT

A system for processing a signal in a signal chain having decentralized embedded power management of components of the signal chain includes an input circuit to generate a measurement signal responsive to a stimulus, where the measurement signal is indicative of a characteristic of the stimulus. The system additionally includes a signal converter circuit coupled to the input circuit to convert the measurement signal to a digital signal according to a timing condition for capturing a sample of the measurement signal. The signal converter includes a control circuit to provide electrical power to the input circuit based on the timing condition and a sampling circuit to capture the sample of the measurement signal responsive to an indicator signal generated by the sensor circuit.

FIELD OF THE DISCLOSURE

This document pertains generally, but not by way of limitation, to dataacquisition circuits and, more particularly, to power management in dataacquisition circuits.

BACKGROUND

Data acquisition systems can include electronic signal chains havingcircuits that obtain analog signals that are indicative of a physicalcondition and convert these analog signals to digital signals forprocessing or analysis. Examples of such signal chains are discussed inU.S. Pat. No. 9,083,369 B2, which is titled “Split-path data acquisitionsignal chain” and was granted to Michael Coin and Lalinda D. Fernando onJul. 14, 2015. The '369 patent discusses a data acquisition systemhaving a signal chain that includes a sensor circuit for generating ananalog signal based on a measured physical condition, a signalconditioning circuit to convert the analog signal to a form suitable forprocessing by a data converter circuit such as a digital-to-analogconverter, a converter circuit for converting the conditioned signal toa digital signal, and a signal processing circuit for further processingthe digital signal. Some data acquisition systems can include signaloffset cancellation components such as auto-zeroing or choppingcircuits. Examples of such offset cancellation circuits are discussed inU.S. Pat. No. 7,834,685 B1, which is titled “Chopped auto-zeroedping-pong amplifier and related apparatus, system, and method” and wasgranted to Michiel Antonius Petrus Pertijs on Nov. 16, 2010. The '685patent discusses an apparatus having a two or more amplifier stages,where at least one amplifier stage operates in an auto-zeroing phasewhen at least one other amplifier stage operates in an amplificationphase.

SUMMARY OF THE DISCLOSURE

A system for processing a signal in a signal chain having decentralizedembedded power management of components of the signal chain can includean input circuit to generate a measurement signal responsive to astimulus, where the measurement signal is indicative of a characteristicof the stimulus. The system can additionally include a signal convertercircuit coupled to the input circuit to convert the measurement signalto a digital signal according to a timing condition for capturing asample of the measurement signal. The signal converter can include acontrol circuit to provide electrical power to the input circuit basedon the timing condition and a sampling circuit to capture the sample ofthe measurement signal responsive to an indicator signal generated bythe sensor circuit.

A system for processing a signal in a signal chain having decentralizedembedded power management of components of the signal chain can includea sensor circuit to generate a measurement signal that is indicative ofa physical quantity, a conditioning circuit that is coupled to an outputof the sensor circuit to provide an adjusted measurement signalaccording to an input circuit criterion, and a conversion circuit thatis coupled to the conditioning circuit to convert a sample of theadjusted measurement signal to a digital signal. The conversion circuitcan include a first control circuit to provide a control signal topower-on the conditioning circuit and to power-off the conversioncircuit responsive to providing control signal to the conditioningcircuit, and a second control circuit to power-on the conversion circuitresponsive to the conditioning circuit providing the adjustedmeasurement.

A method of operating a signal chain having decentralized embedded powermanagement of components can include providing a first control signalfrom the signal converter circuit to a signal conditioning circuit,wherein the first control signal provides power to the signalconditioning circuit to generate a measurement signal. The method canadditionally include powering off the signal converter circuitresponsive to proving the first control signal, obtaining a secondcontrol signal from the signal conditioning circuit responsive to thesignal conditioning circuit generating the measurement signal, andpowering on the signal converter circuit and obtaining a sample of themeasurement signal responsive to receiving the second control signal.

This summary is intended to provide an overview of subject matter of thepresent patent application. It is not intended to provide an exclusiveor exhaustive explanation of the invention. The detailed description isincluded to provide further information about the present patentapplication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an example of a signal chain having embedded powermanagement integrated in a signal conditioning circuit and a dataconverter circuit.

FIG. 1B illustrates an example of electronic signals associated withoperation of a signal chain having embedded power management integratedin a signal conditioning circuit and a data converter circuit.

FIG. 2 illustrates an example of a signal chain having embedded powermanagement integrated in a converter circuit.

FIG. 3A illustrates an example of a signal chain having and embeddedpower management and signal offset cancellation components for reducingconditioning and conversion circuit offsets.

FIG. 3B illustrates an example of a signal chain having and embeddedpower management and autozeroing signal offset cancellation componentsfor reducing conditioning and conversion circuit offsets.

FIG. 4 illustrates an example of a signal chain having and embeddedpower management and signal offset cancellation components for reducingsensor and conversion circuit offsets.

FIG. 4B illustrates an example of a signal chain having embedded powermanagement and autozeroing signal offset cancellation components forreducing sensor and conversion circuit offsets.

FIG. 5A illustrates an example of electronic signals associated withoperation of a signal chain having embedded power management integratedin a converter circuit or a signal conditioning circuit for analogoffset cancellation.

FIG. 5B illustrates an example of electronic signals associated withoperation of a signal chain having power management integrated in asignal conditioning circuit and a data converter circuit for digitaloffset cancellation.

FIG. 6 illustrates an example of handshaking circuit for implementing aprotocol for power management in a signal chain having embedded powermanagement.

FIG. 7 illustrates an example of a process for operating a signal chainhaving embedded power management.

FIG. 8A illustrates an example of a signal chain having embedded powermanagement integrated in a data converter circuit and signalconditioning circuit having a selectable bandwidth.

FIG. 8B illustrates an example of electronic signals associated withoperation of a signal chain having embedded power management integratedin a data converter circuit and signal conditioning circuit having aselectable bandwidth.

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

DETAILED DESCRIPTION

The present disclosure includes techniques for embedded or distributedpower management and offset cancellation in electronic signal chains(hereinafter, “signal chain(s)”). Such techniques can include signalchains where sensor, signal conditioning, or data converter circuits canbe configured to implement a protocol or signalling scheme whereby thedata converter synchronizes the power-on or power-off times of thesignal conditioning circuit or the sensor circuit according to thesample times of the data converter circuit. Such techniques also includesignal chains where sensor, signal conditioning, or data convertercircuits can be configured to implement a protocol or signalling schemewhereby the signal conditioning circuit synchronizes the power-on orpower-off times of the sensor with the power-on and power-off times ofthe signal conditioning circuit. The present techniques can help enablehigher resolution or finer grained power management such as by reducingthe on-time of each component in a signal chain. The techniques can alsohelp facilitate signal offset cancellation within the data convertercircuit without requiring the use of lowpass filters that wouldotherwise be required to attenuate the switching artefacts of the offsetcancellation algorithm inside the signal conditioning circuit.

As used herein, power management includes techniques for turning off orreducing power to one or more components of a system, such as when thesystem or component is not active, such as when the component or systemis not being used to produce a useful signal or result. Powerconsumption can be reduced by reducing or minimizing the power-on timeor power-on duty cycle of the system. A microcontroller or othercentrally located control circuit can implement power management in thesignal chains of data acquisition systems. Such centralized ormicrocontroller-based power management techniques can include powercycling all components of a signal chain together simultaneously tomanage power consumption. Such an approach, however, can result insuboptimal power management as the signal chain component having thelongest power-up or settling time determines or sets the minimumduration of the power-on duty cycle. This can result in one or morefaster components, such a component having shorter power-on or settlingtimes, consuming power while not actively being used to perform work orto generate useful data or signals. In an example, a fast settlinglow-ohmic strain-gauge sensor that is disposed in the same signal chainas a signal conditioning circuit (hereinafter, “conditioning circuit”),such as an amplifier, that has a slow settling time may be powered forthe entire time it takes the amplifier to settle. Additionally, thesesignal chains can perform noise and offset cancellation in theconditioning or data conversion circuits using filters that can havinglong start up times, resulting in additional power waste. For example,conditioning circuits generally use these filters to filter transientsgenerated by chopping or auto-zeroing switches before the output of theconditioning circuit sampled by a data converter. Moreover, such amicrocontroller may not have access to the internal sampling timingcontrol of the data converter, requiring it to add extra timing marginsto the power control signals, resulting in additional energy usage.

Examples of the present disclosure are based on the inventors'recognition that, within a signal chain, the data converter circuit(hereinafter, “converter circuit”) has timing information that isindicative of the exact time it needs a conditioning circuit to providea conditioned signal, and the conditioning circuit has timinginformation that is indicative of the exact time at which its output hassettled and when it is ready for sensor information. The power-on timefor each circuit in a signal chain can be minimized or reduced by usingthe timing information available to the converter circuit and theconditioning circuit, such as to implement a handshaking protocolbetween the conditioning circuit and the converter circuit, and betweenthe conditioning circuit and the sensor circuit to synchronize orsequence the operation or power-on time of each circuit.

Examples of the present disclosure can include techniques (e.g.,devices, systems, and methods) for improving power management in asignal chain and to facilitate signal offset cancellation throughembedded or distributed synchronization or sequencing (hereinafter,“synchronization”) of the operation of the components of the signalchain. In an example, a microcontroller can be configured with computerexecutable code or one or more circuits to configure a converter circuitto capture and digitize one or more samples of an analog signal.Configuring the converter circuit can include setting the convertercircuit sample rate or sample times for obtaining the one or moresamples. To obtain each of the one or more samples, the convertercircuit can be configured to actuate, or provide power to, theconditioning circuit and to power-off and wait for the conditioningcircuit to indicate that an output of the conditioning circuit hassettled or is ready to be sampled by the converter circuit. The dataconverter or the conditioning circuit can be configured to synchronizeoperation of a sensor circuit with operation of the conditioning circuitsuch as by powering-on the sensor circuit immediately after, or incoordination with, the conditioning circuit powering-on. Theconditioning circuit can be further configured to provide a signal tothe converter circuit to capture a sample of the output of theconditioning circuit after, or responsive to, the output of theconditioning circuit settling. The conditioning circuit and the sensorcircuits can then be powered down, such as after a short delay after thesample moment or sample time. The converter circuit can be configured topower-on, capture and digitize a sample of output of the conditioningcircuit responsive to receiving the signal from the conditioningcircuit. The converter circuit can be further configured to power-offafter, or responsive to, digitizing the sample. The converter circuitcan be further configured to alert or wake up the microcontrollerresponsive the converter circuit having one or more digital samplesready to transmit to the controller.

In another example of the present disclosure, the signal chain can beconfigured to cancel signal offsets between the conditioning circuit andthe converter circuit such as through chopping operations whereby theconverter circuit captures first and second samples of the output of theconditioning circuit, sums the two samples in the charge domain, anddigitizes the result of the summation. The path of each sample thoughthe signal chain can be selected or configured such that the signaloffset in the first sample is the negative or opposite polarity of thesignal offset in the second sample, such that the offsets are cancelledby the summation.

In another example of the present disclosure, the signal chain can beconfigured to cancel signal offsets between the signal conditioningcircuit and the data converter circuit through chopping operationswhereby the converter circuit captures first and second samples of theoutput of the conditioning circuit, digitizes each sample, and sums thetwo digitized samples in the digital domain. As previously described,the path of each sample though the signal chain can be selected orconfigured such that the signal offset in the first sample is thenegative or opposite polarity of the signal offset in the second sample,such that the offsets are cancelled by the summation.

In another example, the previously described offset cancellationtechniques can be modified such that the conversion circuit captures afirst sample having the analog signal and a signal offset and a secondsample having only the signal offset. Offset cancellation is thenaccomplished by summation of the two samples such as previouslydescribed.

As used herein, powering-off a circuit includes disconnecting thecircuit from a power supply or reducing the power consumption of acircuit, such as by shutting down or inhibiting the operation of one ormore sub-circuits of the circuit, such as by turning off one or moretransistor or other switching device of the sub-circuit.

FIG. 1A illustrates an example of a signal chain 100 having embeddedpower management integrated in a conditioning circuit 110 and aconverter circuit 115. The signal chain 100 can be used in an electronicdata acquisition system to obtain or process digitized samples of analogsignals that are indicative of, or that include information about, aphysical condition, such as environmental, physiological, mechanical, orelectronic measurements. In an example, such physical conditions includeheartrate, pressure, mechanical stress, speed, acceleration, fluid flowrate, or any other suitable measurable physical quantity. The signalchain 100, in various examples, includes a sensor circuit 105, theconditioning circuit 110, the converter circuit 115, and a controllercircuit 120. One or more components or circuits of the signal chain 100can be configured to communicate with another component of the signalchain using any suitable data or signal communication techniques. In anexample, one or more components of the signal chain 100 can communicateusing a data or signal communication interface to another component oranother system according to a specified communication protocol, such asany of the communication or handshaking protocols described herein. Inan example, the data communication interface includes a single endedsignal interface, a differential signal interface, or a multibit datacommunication bus. In some examples, one or more components of thesignal chain 100 are coupled to, and obtain electrical power form, powersource 145 though power rails 150 (e.g., a positive rail) and 155 (e.g.,a negative or ground rail).

The sensor circuit 105 can include one or more circuits that areconfigured to receive an input signal or stimulus that is indicative ofa physical condition and convert the input received input signal into anelectrical signal (hereinafter, “measurement signal”), such as an analogvoltage or current signal, that is indicative of the physical condition.In an example the sensor circuit 105 includes a sensor device 125 andassociated power or control circuitry, such as the switching circuit160. The sensor device 125 can include any electrical, mechanical,optical, acoustic, or field (e.g., electric, magnetic or gravitationalfield) sensitive device that is configured to detect or measure aphysical condition. The switching circuit 160 can include a controllableelectronic switch, such as a transistor circuit or electromechanicalswitch circuit. The switching circuit can be configured to receive acontrol signal 162 and, responsive to the control signal (e.g., based onreceiving the control signal a first time or based a specified firstsignal value of the control signal), power-on the sensor circuit 105.Powering-on the sensor circuit 105 can include coupling the sensordevice 125 to the positive power rail 150 or to the negative power rail155 of the power supply 145, such as to actuate the sensor circuit togenerate a measurement signal that is indicative of a physicalcondition. In an example, the switching circuit 160 is configured topower-off the sensor circuit 105, responsive to the control signal 162(e.g., based on receiving the control signal a second time or based asecond signal value of the control signal). In an example, the controlsignal 162 is obtained from the conditioning circuit 110 through apoint-to-point electrical connection to the conditioning circuit orthrough a data communication bus having one or more electrical channels.The control signal 162 can include any signal that can be controllableswitched between at least two electrical states. In an example, thecontrol signal 162 includes a voltage or current having one or morespecified magnitudes, a signal having one or more specified frequencies,or one or more quantized, digital, or binary values.

The sensor circuit, while powered-on, is configured to generate ameasurement signal, such as a differential signal 168, that isindicative of a physical condition and to provide the measurement signalto the conditioning circuit 110.

The conditioning circuit 110 includes one or more circuits that areconfigured to receive a measurement signal from a sensor circuit, suchas the sensor circuit 105, and to condition the measurement signalaccording to an input signal specification or requirement of the dataconverter. In an example, the conditioning circuit conditions themeasurement signal by adjusting one or more electrical characteristics(e.g., voltage or current amplitude, signal frequency, or pulse risetime, fall time, or width) of the measurement signal to transform themeasurement signal to a conditioned measurement signal. The adjustedelectrical characteristics of the conditioned measurement signal arewithin a range suitable for a converter or sampling circuit, such as theconverter circuit 115. In an example, the conditioning circuit 110includes a buffer circuit, such as a differential amplifier circuit 135,and switching circuit 164. The differential amplifier circuit 135 caninclude any suitable amplifier circuit that is configured with an inputstage to receive an output of the sensor circuit 105 as differentialmeasurement signals 168 and an output stage to provide the conditioneddifferential output signals 130.

In an example, the differential amplifier circuit 135, or conditioningcircuit 110, includes one or more amplifier control circuits thatimplements a handshaking or synchronizing protocol with the convertercircuit 115 using the control signal 174. An amplifier control circuit,for example, can determine that the output of the amplifier circuit 135has settled, such as by determining that switching noise or high speedtransients present in the amplifier output are attenuated or decreasedbelow a threshold signal level (e.g., a threshold voltage or currentlevel). The amplifier control circuit, in another example, determineswhether the output of the amplifier circuit 135 has settled based on, orby using, a pre-programed reference value that is indicative of thesettling time of the amplifier output. In an example, the pre-programmedreference value includes a pre-programmed timer or pre-programmed delaythat is used a reference indicative of the settling time. The amplifiercontrol circuit then actuates the control signal 174 to signal to theconverter circuit that the output of the amplifier circuit 135 orconditioning circuit 110 is ready to be sampled. The amplifier controlcircuit can also operate in coordination with the switching circuit 164,such as discussed with respect to FIG. 6, to disable or power-off theamplifier circuit 135 or the conditioning circuit 110 responsive toproviding the control signal 174 and after a short delay (e.g., a delaycorresponding to a setup or hold time of the converter circuit 115).

The switching circuit 164 can include a controllable electronic switch,such as a transistor circuit or electromechanical switch circuit, or anyother circuit that is configured to receive a control signal 174, suchas from the converter circuit 115, and adjust the operating state (e.g.,a power-on, power-off, lower-power, or normal operating state) of theconditioning circuit to affect the power efficiency or power consumptionof the conditioning circuit. In an example, responsive to the receivingthe control signal or responsive to a value of the control signal, theswitching circuit 164 powers-on the conditioning circuit 110 or theamplifier circuit 135, such as by coupling the conditioning circuit 110to the positive power rail 150 or the negative power rail 155 of thepower supply 145, such as to actuate the conditioning circuit tocondition or adjust the measurement signal 168 such as described herein.In another example, the switching circuit 164 is also configured topower-off the amplifier circuit 135 responsive to the control signal 174(e.g., based on receiving the control signal a second time or based asecond signal value of the control signal). In yet another example,rather than being configured to disconnect or decouple the power supply145 from the conditioning circuit 110, the switching circuit 164 isconfigured with one or more gating, driver, or control circuit topower-on, power-off, or otherwise adjust the operating state of theconditioning circuit responsive to the receiving the control signal orresponsive to a value of the control signal using any suitabletechnique.

In an example, the amplifier circuit 135 includes a sensor controlcircuit (not shown) to generate the control signal 162. The sensorcontrol circuit is configured to power-on the sensor circuit 105, suchas by actuating the control signal 162 to actuate the switching circuit160 to couple the sensor circuit to the power supply 145, after theconditioning circuit 110 is powered-on or powered-up. The sensor controlcircuit is further configured to power-off the sensor circuit 105, suchas by actuating the control signal 162 to actuate the switching circuit160 to disconnect or decouple the sensor circuit from the power supply145, synchronous with, or responsive to, the conditioning circuit 110being powered-off.

In another example, the conditioning circuit 110 includes one or moreauto-zeroing or chopping circuits, such as the electronic commutatorsdescribed in the discussion of FIGS. 3A, 3B, 4A, and 4B, such as forcancelling signal offset at the inputs of the differential inputs to theconverter circuit 110. The auto-zeroing or chopping circuits arecontrollable to provide offset cancellation through actuation of thechop signal 174, such as described in the discussion of FIGS. 3A, 3B,4A, and 4B.

The converter circuit 115 includes one or more circuits that areconfigured to receive an electrical signal that is indicative of aconditioned measurement signal, such as the conditioned differentialsignal generated by the conditioning circuit 110, and to obtain one ormore digital samples of the electrical signal. The digital samples ofthe electrical signal can include a discrete voltage or a sequence ofone or more digital values that is indicative of an electricalcharacteristic of the electrical signal. In an example, the convertercircuit 115 generates a set of discrete voltages that are indicative ofa binary or binary coded decimal representation of the magnitude of avoltage or current that corresponds to an measurement signal generatedby the sensor circuit 105 or the conditioned measurement signalgenerated by conditioning circuit 110. In another example, the convertercircuit 115 generates a set of digital samples as a set of discreteelectrical pulses that are indicative of a binary or binary codeddecimal representation of a frequency of the measurement signalgenerated by the sensor circuit 105 or the conditioned measurementsignal generated by conditioning circuit 110.

The converter circuit 115 can include a sampling circuit, such as theanalog-to-digital converter (ADC) circuit 140, and a control circuit192. The converter circuit 115 can further include a switching circuit170. In some examples, the controller circuit 192 is a sub-circuit ofthe sampling circuit or ADC circuit 140.

The sampling circuit or the ADC circuit 140 can include one or morecircuits that are configured to obtain digital samples of an electricalsignal as described herein.

The switching circuit 170 is an embodiment of the switching circuit 164and can include a controllable electronic switch or other switchingcircuit, such as a transistor circuit or electromechanical switchcircuit, that is configured to receive a control signal from the controlcircuit 192 and, responsive to the control signal, power-on theconverter circuit 110 or the ADC circuit 140, such as by coupling theconverter circuit to the positive power rail 150 or the negative powerrail 155 of the power supply 145, such as to actuate the convertercircuit to obtain one or more digital samples of an electrical signal.In an example, the switching circuit 170 is configured to power-off theconverter circuit 115 or the ADC circuit 140 responsive to the controlsignal (e.g., based a second signal value of the control signal).

The control circuit 192 includes one or more circuits that areconfigured to interface with one or more components of the signal chain100 to actuate the converter circuit 115 implement or execute thetechniques described herein. The control circuit 192, in an example,includes one or more programmable combinational or sequential digitallogic circuits, such as a microcontroller, a programmable gate array, orstate machine. In another example, the control circuit 192 isconfigured, such as by software or one or more specially configuredcircuits, to interface with the controller circuit 120 or the ADCcircuit 140 to obtain configuration information for the convertercircuit 115. The configuration information includes electronic data orother digital signals that are indicative of, or that specifies, thesampling configuration of the converter circuit 115. In an example, theconfiguration information specifies the number of digital samples theconverter circuit 115 is configured to obtain, the sample rate of theconverter circuit, the frequency at which samples are obtained, thesample moments (e.g., absolute or relative sampling times) of theconverter circuit, or any other timing, configuration, or, statusinformation that is useful for determining that the converter circuitshould power-on, such as to perform sampling operations, or powered-off,such as to conserve power or battery life. The control circuit 192, inan example, is coupled to the power supply 145 or to another powersupply independent of the operation of switching circuit 170, such thatthe control circuit can be remain powered when the switching circuit 170is actuated to power-off the converter circuit 115.

The control circuit 192 is configured to determine, such as based on apre-programmed sample moment obtained from the converter circuit 115,that the converter circuit is ready to capture or obtain a digitalsample of an electrical signal. The control circuit 192 is furtherconfigured to generate, responsive to determining that the convertercircuit 115 is ready to obtain a digital sample, a control signal, suchas the control signal 174, to power-on the conditioning circuit 110. Thecontrol circuit 192 is additionally configured to generate a controlsignal to actuate the switching circuit 170 to power-off the convertercircuit after powering-on the conditioning circuit 110. The controlcircuit 192 is further configured to receive a control signal (or astatus signal) from the conditioning circuit 110 that indicates that anelectrical signal, such as a conditioned measurement signal, isavailable at the output of the conditioning circuit for sampling and,responsive to receiving the control signal, generating another controlsignal to actuate the switching circuit 170 to power-on the convertercircuit 115 or to actuate the converter circuit to obtain a digitalsample. The control circuit 192 is further configured to generate a chopsignal or an auto zero phase signal (hereinafter, commutator signal 172)to synchronize the converter sample cycle with the operation of choppingor auto zeroing electronic commutators described in the discussion ofFIGS. 3-4.

The controller circuit 120 can include a microprocessor,microcontroller, digital signal processor, programmable gate array, orany other suitable logic or computing circuit that is configured toreceive one or more digital samples of an electrical signal, such as aconditioned measurement signal generated by the converter circuit 115.In an example, the controller circuit 120 includes a control logic and amemory. The control logic is configured, such as by one or more hardwarecircuits or computer executable code or software, to cause thecontroller circuit 120 to actuate the converter circuit 115 to obtainthe digital samples and to store the digital samples in the memory, suchas for further processing by the controller circuit 120 or for provisionto another circuit or system. In an example, actuating the convertercircuit 115 to obtain the digital samples includes configuration one ormore circuits of the converter circuit 115 to specify a sample rate,sample moment, sample resolution, sample size, or any other parameterthat is useful for enabling the operation of the converter circuit. Inanother example, actuating the converter circuit 115 includes causing ortriggering, such as by actuating a convert-start pin or input of theconverter circuit, the converter circuit to initiate a sampling anddigitization operation. The controller circuit 120 can also include oneor more circuits that are configured to power-off the controller orplace the controller in a lower or reduced power state responsive to, orafter, actuating the conversion circuit 115. The controller circuit 120can include another circuit to power-on the controller responsive to thecontroller receiving a signal from the converter circuit 115 indicatingthat the digital samples are available for transfer or processing.

In an example of operation of the signal chain 100, the controllercircuit 120 interfaces with the converter circuit 115 or the controlcircuit 192 to configure the converter circuit obtain a set of one ormore digital samples at a specified sample rate and at one or morespecified sample moments. The controller circuit 120 may then enter alow-power or powered-off mode until the converter circuit signals thatthe digital samples are ready to be transmitted to the controllercircuit. For each digital sample, the control circuit 192 may actuatethe switching circuit 170 to power-on the converter circuit 115responsive to determining, such as based on the programmed sample rateor sample moments, that the converter circuit is ready to capture orobtain digital sample. The converter circuit 115, or the control circuit192, actuates the switching circuit 164 to power-on the conditioningcircuit 110. The converter circuit is then automatically powered-offafter a short delay. In an example, the switching circuit 160 isactuated by the conditioning circuit 110 to power-on the sensor circuit105 responsive to the conditioning powering-on or responsive to anothertiming condition. In another example, the switching circuit 160 isactuated by the converter circuit 115, or by the control circuit 192, topower-on the sensor circuit 105 responsive to the conditioning circuit110 powering on or responsive to another timing condition. Theconditioning circuit 110 obtains a measurement signal from the sensorcircuit 105 and generates a conditioned measurement signal ondifferential outputs 130. The conditioning circuit 110, or an amplifiercontrol circuit disposed within the conditioning circuit, monitors thedifferential outputs 130 to determine when the outputs have settled and,responsive to determining that the output have settled, provide acontrol signal 174 to signal the converter circuit 115 to obtain asample of the outputs. After a short delay, such as a delay or at least1 nanosecond, the conditioning circuit 110 and the sensor circuit 105are powered off. In an example, the conditioning circuit automaticallypowers-off itself and the sensor circuit 105. In another example, theconverter circuit 115 powers-off the conditioning circuit 110 and thesensor circuit 105 after a short delay from a specified sample moment.The converter circuit 115 powers-on responsive to receiving the controlsignal 174 from the conditioning circuit 110, captures of digitizes thesample and then powers-off. In some examples, the converter circuit 115wakes up the controller circuit 120 after a specified number of digitalsamples are ready to be transferred from the converter to thecontroller.

Although FIG. 1A and the remaining figures and associated discussionsillustrate and describe the sensor signal 168, the output of theconditioning circuit 130, or other similar or corresponding signals aredifferential signals, these signals, in various examples, can be singleended signals. In such examples, one signal wire, or one end of thedescribed differential signals, is or can be held or maintained at aconstant electrical signal level, such as by being connected to ground,a reference voltage, or a common mode voltage.

FIG. 1B illustrates an example of signals associated with operation of asignal chain, such as the signal chain 100, having embedded powermanagement integrated in a signal conditioning circuit, such as theconditioning circuit 110, and a converter circuit, such as the convertercircuit 115. In an example, FIG. 1B illustrate signal that are generatedby one or more components of the signal chain 100 during operation. Asshown in FIG. 1B, the CHOP signal 176 is an example of the commutatorsignal 172, the START/SAMPLE signal 178 (hereinafter, “SAMPLE signal178”) is an example of the switching circuit control signal 174, theSENSOR ENABLE signal 180 is an example of the switching circuit controlsignal 162, and the CONVERTER ACTIVE signal 182 provides an indicationof whether the converter circuit 115 is active or powered-on.

As shown in FIG. 1B, the SAMPLE signal 178 is actuated, or driven to alogical high voltage, such as by the converter circuit 115, to power-onthe conditioning circuit 110 at time T1. The conditioning circuitpowers-up during time span 184 between time T1 and T2. At time T2, theSENSOR ENABLE signal 180 is actuated, such as by the conditioningcircuit 110 or the converter circuit 115, to power-on the sensor circuit105. During the time span 186 between time T2 and time T3, the sensorcircuit 105 provides a measurement signal to the conditioning circuit110 which in turn generates a conditioned measurement signal and waitsuntil its outputs settle at T3 to actuate the SAMPLE signal at thefalling edge of 178 to signal to the converter circuit 115 to capture orobtain a digital sample. At time T3, the converter circuit 115 powers-onto capture a digital sample, such as indicated by CONVERTER ACTIVEsignal 182. The converter circuit is active obtaining a digital sampleduring the time span 188 between T3 and T4. The sensor circuit 105 isactive during the time span 186 and the conditioning circuit 110 isactive during the time span 190.

FIG. 2 illustrates an example of a signal chain 200 having embeddedpower management integrated in a converter circuit 210. The signal chain200 is an example of the signal chain 100 wherein the conditioningcircuit 110 and the converter circuit 115 are replaced by conditioningcircuit 205 and converter circuit 210. Conditioning circuit 205 is anexample of the conditioning circuit 110 that is modified to decouple ordisconnect the conditioning circuit from the control terminal of theswitching circuit 160. The converter circuit 210 is an example of theconverter circuit 115 that is modified to couple or connect theconverter circuit, or the control circuit 192 to the control terminal ofthe switching circuit 160. The operation of the signal chain 200 isidentical to the operation of the signal 100, with the exception thatthe switching circuit 160 is actuated by the converter circuit 210, suchas through actuation of the control signal 215, to power-on or power-offthe sensor circuit 105. In an example, the converter circuit 210,actuates the control signal 215 to synchronize operation of the sensorcircuit 105 with operation of the conditioning circuit 205 as discussedin FIGS. 1A and 1B. In another example, the converter circuit 210,actuates the control signal 215 to power-on or power-off the operationof the sensor circuit 105 according one or more other specified timingconditions.

FIG. 3A illustrates an example of a signal chain 300 having and embeddedpower management and chopping signal offset cancellation components forreducing conditioning and conversion circuit offsets. FIG. 3Billustrates an example of a signal chain 340 having and embedded powermanagement and autozeroing signal offset cancellation components forreducing conditioning and conversion circuit offsets. The signal chain300 and 345 are examples of the signal chain 100 wherein theconditioning circuit 110 and the converter circuit 115 are replaced byconditioning circuit 305 and converter circuit 310. Conditioning circuit305 is an example of the conditioning circuit 110 that is modified toinclude an electronic commutator circuit 315 at the input to theconditioning circuit. The converter circuit 210 is an example of theconverter circuit 110 that is modified to include an electroniccommutator circuit 320 at the input to the converter circuit. In anexample, the electronic commutator circuit 315 (FIG. 3A), or the connectswitch 345 (FIG. 3B), and the electronic commutator 320 are respectivecomponents of the amplifier circuit 135 and the ADC circuit 140. In FIG.3A, the converter circuit 310 switches the electronic commutator circuit315 and the electronic commutator 320 through actuation of thecommutator signal 325. In FIG. 3B, the converter circuit 310 switchesthe connect switch 345 and the electronic commutator 320 throughactuation of the commutator signal 325.

In operation, the signal chain 300 operates identically to the signalchain 100, with the exception that the converter circuit 310 capturestwo digitals samples for each digital sample of an electrical signal itis configured to obtain. In an example when the signal chain 300 isconfigured to cancel signal offsets using chopping techniques, as shownin FIG. 3A, the converter circuit 310 captures, for each digital sampleof an electrical signal it is configured by the controller circuit 120to obtain, a first and a second analog sample. The first analog sampleis taken with commutators 315 and 320 in a non-inverting position andincludes the sum of a sample of the electrical signal and a first signaloffset developed while the electronic signal is conducted along a firstpath through the conditioning circuit 305 and the converter circuit 310.After obtaining the first digital sample, the converter circuit 310synchronously switches the electronic commutator circuit 315 and theelectronic commutator 320 to an inverting position to obtain a seconddigital sample. The second analog sample includes the sum of a secondsample of electrical signal and a second offset developed while theelectronic signal is conducted along a second path through theconditioning circuit 305 and the converter circuit 310. In an examplethe first and second offsets have substantially similar or identicalamplitudes and opposite polarity. In another example, when the signalchain 300 is configured to cancel signal offsets using auto zeroingtechniques as shown in FIG. 3B, the converter circuit 310 captures, foreach digital sample of an electrical signal that the converter circuitis configured by the controller circuit 120 to obtain, a first and asecond analog samples. The first analog sample includes only a firstoffset developed while the electronic signal is conducted along a firstpath through the conditioning circuit 305 and the converter circuit 310and no signal. In a first configuration, the connect switch 345 isconfigured to disconnect the sensor circuit 105 and to zero the input(s)of signal conditioning circuit 135 together while the commutator 320inverts the output(s) of conditioning circuit. The second analog sample,obtained after synchronously switching the connect switch 345 and theelectronic commutator so that the sensor signal 168 is passed on toconditioning circuit 305, includes the sum of a sample of the electricalsignal and a second signal offset developed while the electronic signalis conducted along a second path through the conditioning circuit 305and the converter circuit 310.

In some examples, a sequence or order of obtaining any of the first andsecond samples described herein is arbitrary and can therefore bereserved from the order sequence or order described in the presentdisclosure.

The two analog samples are then combined by add or subtracting thesamples. In an example, each sample can be stored as a charge in acapacitor and then combined in the charge domain before the sum issampled by the converter circuit 310. In another example the samples aredigitized and then combined (e.g., added or subtracted in the digitaldomain). These techniques cancel signal offsets contributed by theconditioning circuit, by manufacturing imperfections inside the signalconditioning circuit or by the thermocouple formed by the wiring betweenthe data converter and the conditioning circuit, by the convertercircuit.

FIG. 4A illustrates an example of a signal chain 400 having embeddedpower management and chopping signal offset cancellation components forreducing sensor and conversion circuit offsets. FIG. 4B illustrates anexample of a signal chain 435 having embedded power management andautozeroing signal offset cancellation components for reducing sensorand conversion circuit offsets. The signal chains 400 and 435 areexamples of the signal chain 100 wherein the sensor circuit 105 and theconverter circuit 115 are replaced by sensor circuit 405 and convertercircuit 410. In FIG. 4A, sensor circuit 405 is an example of the sensorcircuit 105 that is modified to include an electronic commutator circuit415 at the power supply input to the sensor circuit. The convertercircuit 410 is an example of the converter circuit 110 that is modifiedto include an electronic commutator circuit 420 at the input to theconverter circuit. In an example, the electronic commutator circuit 415(FIG. 4A) and the electronic commutator 420 are respective components ofthe sensor device 125 and the ADC circuit 140. The converter circuit 410switches the electronic commutator circuit 415 and the electroniccommutator 420 through actuation of the commutator signal 425. Thesignal chain 400 operates identically to the signal chain 300, with theexception that the sensor circuit and signal converter offsets arecancelled in this configuration. The signal chain 435 operates similarlyto the signal chain 345, with the exception that before the first analogsample is captured, the physical condition or input that is beingmeasured (e.g., pressure or weight) is removed from the sensor 125,while commutator switch 420 is in an inverting position. Additionally,before the second analog sample is captured, the physical condition orinput is applied to the sensor 125, while commutator switch 420 is in anon-inverting position.

FIG. 5A illustrates an example of electronic signals associated withoperation of a signal chain having embedded power management integratedin a signal conditioning circuit or a converter circuit for analogoffset cancellation. In an example, FIG. 5A illustrate signals that aregenerated by one or more components of the signal chain 300 or 400during operation. As shown in FIG. 5A, CHOP/AZ signal 505 is an exampleof the commutator signal 325 or 425, the START/SAMPLE signal 510 is anexample of the switching circuit control signal 174, the SENSOR ENABLEsignal 515 is an example of the switching circuit control signal 162,and the CONVERTER ACTIVE signal 520 provides an indication of whetherthe converter circuit 310 or 410 is active or powered-on.

As shown in FIG. 5A, the CHOP/AZ signal 505 is actuated or driven highat time T1 to select a first configuration of the electronic commutatorfor obtaining a first sample of a measurement signal at the convertercircuit 310 or 410, as described herein. Additionally, START/SAMPLEsignal 510 is actuated or driven high at time T1 to power-on theconditioning circuit 110 or 305. The conditioning circuit 110 or 305powers up during time span 525 between time T1 and T2. When the signalchain 300 or 400 is configured to use chopping to cancel signal offsets,the sensor enable signal 515 is actuated at time T2 and remains highuntil time T4 to power-on the sensor circuit 105 or 405 and to keep thesensor on long enough to obtain two samples of the measurement signals.When the signal chain 300 or 400 is configured to use auto-zeroing tocancel signal offsets, the sensor enable signal 515 is actuated ateither time T2 or T3 and remains until either time T3 or T4respectively, such as to power-on the sensor circuit 105 or 405 on longenough to obtain one sample of the measurement signals. During the timespan 530 between time T2 and time T3 or during the time span 535 betweenT3 and T4, the sensor circuit provides a measurement signal to theconditioning circuit 110 or 305. At time T3, a first sample of aconditioned measurement signal generated by conditioning circuit 110 or305 is obtained in the analog domain, such as by storing the sample as acharge on a first capacitor. The first sample, for a chopping signalchain, includes the sum of a sample of conditioned measurement signaland a first signal offset. The first sample, for an auto zeroing signalchain, includes a sample of a first signal offset without theconditioned measurement signal. At time T4, a second sample of aconditioned measurement signal is obtained in the analog domain, such asby storing the sample as a charge on a second capacitor. The secondsample, for a chopping signal chain, includes the sum of a sample ofconditioned measurement signal and a second signal offset, as describedherein. The second sample, for an auto zeroing signal chain, includesthe sum of a sample of conditioned measurement signal and a secondsignal offset, as described herein. The converter circuit is alsopowered on at T4 to obtain a digital sample the sum of the first andsecond samples during the time span 540. Additionally, at time T4, theconditioning and sensor circuits are powered-off as indicated bySTART/SAMPLE signal 510 and SENSOR ENABLE signal 515 transitioning low.

FIG. 5B illustrates an example of electronic signals associated withoperation of a signal chain having power management integrated in aconverter circuit or a signal conditioning circuit for digital offsetcancellation. In an example, FIG. 5B illustrate signals that aregenerated by one or more components of the signal chain 300 or 400during operation. As shown in FIG. 5B, CHOP/AZ signal 555 is an exampleof the commutator signal 325 or 425, the START/SAMPLE signal 560 is anexample of the switching circuit control signal 174, the SENSOR ENABLEsignal 565 is an example of the switching circuit control signal 162,and the CONVERTER ACTIVE signal 570 provides an indication of whetherthe converter circuit 310 or 410 is active or powered on.

As shown in FIG. 5B, the CHOP/AZ signal 555 is actuated or driven highat time T1 to select a first configuration of the electronic commutatorfor a first sample, as described herein. Additionally, START/SAMPLEsignal 560 is actuated or driven high at time T1 to power-on theconditioning circuit 110 or 305. The conditioning circuit powers upduring time span 575 between time T1 and T2. When the signal chain 300or 400 is configured to use chopping to cancel signal offsets, theSENSOR ENABLE signal 565 is actuated at time T2 and remains high untiltime T4 to power-on the sensor circuit 105 or 405 and to keep the sensoron long enough to obtain two samples of the conditioned measurementsignal in the digital domain. When the signal chain 300 or 400 isconfigured to use auto zeroing to cancel signal offsets, the SENSORENABLE signal 565 is actuated at either time T2 or T3 and remains highuntil either time T3 or T4 respectively, such as to power-on the sensorcircuit 105 or 405 on long enough to obtain one sample of theconditioned measurement signal in the analog domain. During the timespan 580 between time T2 and time T3 or during the time span 585 betweenT3 and T4, the sensor circuit provides a measurement signal to theconditioning circuit. At time T3, a first sample of the conditionedmeasurement signal is obtained in the digital domain, such as bypowering on the converter circuit to capture the digital sample and thenturn off, such as indicated by pulse 572 in CONVERTER ACTIVE signal 570.The first sample, for a chopping signal chain, includes the sum of asample of conditioned measurement signal and a first signal offset. Thefirst sample, for an auto zeroing signal chain, includes a sample of afirst signal offset without the conditioned measurement signal. At timeT3, the electronic commutators are synchronously switched, such asindicated CHOP/AZ signal 555, to swap the electrical path that themeasurement signals to arrive at the input of the converter circuit. Attime T4, a second sample of a conditioned measurement signal is obtainedin the digital domain, such as by powering on the converter circuit tocapture the digital sample and then turn off, such as indicated by pulse574 in CONVERTER ACTIVE signal 570. The second sample, for a choppingsignal chain, includes the sum of a sample of conditioned measurementsignal and a second signal offset, as described herein. The secondsample, for an auto zeroing signal chain, includes the sum of a sampleof conditioned measurement signal and a second signal offset, asdescribed herein. The converter circuit is also powered on at T4 toobtain a digital sample the sum of the first and samples during the timespan 590. Additionally, at time T4, the conditioning and sensor circuitsare powered-off as indicated by START/SAMPLE signal 560 and SENSORENABLE signal 565 transitioning low. At time T5, the first and seconddigital samples are summed in the digital domain to cancel signaloffsets.

FIG. 6 illustrates an example of handshaking circuit 600 forimplementing a protocol for power management in a signal chain havingembedded power management. The handshaking circuit 600 is an example ofa single wire handshake interface between a conditioning circuit, suchas the conditioning circuit 110 or 305 and a converter circuit, such asthe converter circuit 115, 310 or 410. In an example, the conditioningcircuit is an amplifier circuit, such as the differential amplifier 13,and the converter circuit is an ADC circuit, such as the ADC 140. Thehandshaking circuit 600 includes amplifier control circuit 605 and ADCcontrol circuit 610. In an example, the amplifier control circuit 605 isa sub-circuit of the amplifier control circuit described in thediscussion of FIG. 1A, and the ADC control circuit is a sub-circuit ofthe control circuit 192. The amplifier control circuit includescombinational logic circuit 615 (e.g., a logical OR gate), delay circuit625, combinational logic circuit 630 (e.g., a logical AND gate),switching circuit 645, and weak keeper circuit 640. In another example,the ADC control circuit 610 includes a weak keeper circuit 650,switching circuit 655, combinational logic circuit 660 (e.g., a logicalAND gate), inverting buffers 670 and 680, and delay circuit 675. Thedelay circuit 625 or 675 can include one or more circuits that areconfigured to buffer of delay the passage of an electrical signal fromone node in a circuit to another. The keeper circuit 640 or 650 caninclude one or more circuits that are configured to weakly hold a nodeat a low or high value, such as when the node not driven by an externalcircuit. The switching circuit 645 or 655 is an example of the switchingcircuit 164 or 170, as showing in FIG. 1.

In operation, the ADC control circuit 610 is configured to actuate theamplifier control circuit 605 to power-on the amplifier circuit to beresponsive to the ADC signalling that is ready to obtain a digitalsample of a conditioned measurement signal. The amplifier controlcircuit 605 is configured to signal the ADC circuit the output of theamplifier has settled and ready for sampling by the ADC. The amplifiercontrol circuit 605 is further configured disable the amplifier after ashort delay, such as specified by delay circuit 625, after signallingthe ADC circuit that the output of the amplifier has settled.

In an example, the ADC control circuit 610 receives a start signal 665,such as from the convert-start pin of the ADC circuit. A logical highvoltage on the start signal 665 primes along with an initial logical lowvoltage on the signal 690 (e.g., control signal 174 in FIG. 1A) actuatesthe combinational logic circuit 660 to close the switching circuit 655,thereby coupling the positive power rail VDD to the signal 690.Additionally, the logical high voltage on the start signal 665 enablesthe keeper 650 hold the high voltage on signal 690. After a short delaydetermined inverting buffer 670 and delay circuit 675, the output ofcombinational logic circuit 660 is driven low, opening the switchingcircuit 655 and decoupling or disconnecting the signal 690 from thepositive power rail VDD. Signal 690 is maintained at a high voltage bythe keeper 650. The high voltage on signal 690 powers on the amplifiercircuit by driving the amplifier enable signal 620 high through a highoutput at the combinational logic signal 615. After the output of theamplifier circuit has settled, a monitoring circuit in the amplifiercontrol circuit provide a sample signal 635, such as to indicate thatthe output of the amplifier ready to for sampling. A high voltage onsample signal 635 drives the output of combinational logic circuit 630high while enabling the keeper 640 hold the voltage on signal 690voltage. The high output at the combinational logic circuit 630 closesthe switching circuit 645, thereby coupling the signal 690 to groundpower rail. Additionally, the high voltage on sample signal 635 enablesthe keeper 640 to hold the low voltage on signal 690. The low voltage onsignal 690 drives the sample signal 685, thereby powering-on orsignalling the ADC circuit to sample the output of the amplifier. Aftershort delay determined by delay circuit 625 and combinational logiccircuit 630, the switching circuit 645 is actuated to open by a lowoutput at the combinational logic circuit, thereby decoupling ordisconnecting the signal 690 from the ground power rail. The signal 690,however is weakly maintained low by the keeper 640. The amplifier isalso disabled or powered after the short delay determined by delaycircuit 625 when the chop signal 620 is low.

FIG. 7 illustrates an example of a set of process 700 for operating asignal chain having embedded power management. In an example, one ormore operations of the process 700 are implemented or executed by one ormore components of a signal chain, such as any of the signal chainsdescribed herein. In an example, one or more operations of the process700 are implemented by signal conditioning circuit such as theconditioning circuit 110, a data converter circuit such as the convertercircuit 115, or a handshaking circuit, such as the handshaking circuit600.

At 705, a first control signal is provided to a signal conditioningcircuit, such as the conditioning circuit 110 (FIG. 1). In an examplethe control signal is provided by a data converter circuit, such as toenable or provide power to the signal conditioning circuit, such asenable to signal conditioning circuit to power up and generate ameasurement signal (e.g., a conditioned measurement signal). Enabling orproviding power to the signal conditioning circuits, in variousexamples, includes causing the control signal to actuate a switchingcircuit, such as the switching circuit 164, to couple a power supplyinput of the signal conditioning circuit to a power rail of a powersupply, such as the power supply 145. In other examples, enabling orproviding power to the signal conditioning circuits includes actuatingan enable pin or terminal of the conditioning circuit actuate one ormore internal circuits of the signal conditioning circuit to enable orprovide power to the signal conditioning circuit.

At 710, the data converter circuit is powered-off or placed in alow-power mode a short delay after providing the control signal to thesignal conditioning circuit.

At 715, a second control signal is obtained from the signal conditioncircuit, such as to indicate that the output of the signal conditioningcircuit has settled and is ready to be sampled by the data convertercircuit. In an example, the second controller signal is generated by thecontrol or monitoring circuit response to generating a stable or settledmeasurement signal at the out of the signal conditioning circuit.

At 720, the data converter circuit is powered on and actuated,responsive to receiving the second control signal, to obtain a digitalsample of the measurement signal generated by the signal conditioncircuit. In some examples, the data converter circuit is automaticallypowered off after obtaining the digital sample. The process 700 caninclude any other operation that is suitable for implementing thetechniques described herein. In an example, the process 700 includes oneor more operations to cancel offset signal noise using one or more ofthe auto-zero or chopping techniques described herein. In anotherexample, the process 700 includes one or more operations to actuate thesignal conditioning circuit or the data converter circuit to synchronizeoperation of a sensor circuit, such as the sensor circuit 105, withoperation of the signal conditioning circuit or another timingcondition.

FIG. 8A illustrates an example of a signal chain 800 having embeddedpower management integrated in a data converter circuit and signalconditioning circuit having a selectable bandwidth. The signal chain 800is an example of the signal chain 100 wherein the conditioning circuit110 and the converter circuit 115 are replaced by conditioning circuit805 and converter circuit 810.

Conditioning circuit 805 is an example of the conditioning circuit 110that is modified to include one or more filtering or bandwidthconfiguration circuits that configure the conditioning circuit byadjusting or changing the signal bandwidth of the conditioning circuitbetween at least two bandwidth configurations. In an example, suchbandwidth configurations include a low bandwidth configuration, such asfor processing signals low frequency signals such as a direct current(DC) signal, and a high bandwidth configuration, such as for processingsignals having desired or target frequency components that are above orwithin a threshold frequency. The signal conditioning circuit 805 in thelow bandwidth configuration can consume less power than the signalconditioning circuit in the high bandwidth configuration. In an example,the reduction in power consumption is obtained by reducing bias currentsof one or more transistors of the signal conditioning circuit. This mayresult in a higher spectral noise density in signals processed throughthe conditioning circuit 805, but signal to noise ratio is preserved dueto the reduced noise bandwidth. The signal conditioning circuit 805 inthe high bandwidth configuration can have reduced power-up or power-downtimes, such as due to stronger bias currents used to drive internaltransistors.

In an example, the signal conditioning circuit 805 include a control pinor input to receive a control signal, such as the control signal 815, toactuate filtering or bandwidth configuration circuits to select betweenthe at least two bandwidth configurations.

The converter circuit 810 is an example of the converter circuit 115that is modified to include one or more circuits that are programmable,or configurable, to control a signal filtering characteristic of thesignal converter 805, such as by providing the control signal 815 to,for example, configure the signal conditioning circuit for a lowbandwidth or a high bandwidth operation. The converter circuit 810 canalso be modified to include one or more filtering or bandwidthconfiguration circuits that configure the converter circuit adjusting orchanging the signal bandwidth of the converter circuit between at leasttwo bandwidth configurations, such as described for signal conditioningcircuit 805.

The operation of the signal chain 200 is identical to the operation ofthe signal 100, with the exception that the converter circuit 810 canactuate the control signal 815 to configure the signal conditioningcircuit for a low bandwidth or a high bandwidth. In an example, theconverter circuit 810, actuates the control signal 815 to configure thesignal conditioning circuit 805 to a low bandwidth configuration whilethe conditioning circuit is powering up or powering down, such as toreduce power-up or power-down times, thereby increasing the speed atwhich the conditioning circuit can be power cycled. In another example,the converter circuit 810, actuates the control signal 815 to configurethe signal conditioning circuit 805 to a high bandwidth configurationafter power-up, such as in circumstances where the signals to theconditioning circuit are low frequency or DC signals. In yet anotherexample, the converter circuit 810 adjusts the filtering or bandwidthconfiguration of the signal conditioning circuit 805 or the signalbandwidth or sample rate of the converter circuit to control the powerefficiency, or to effect power management, of the signal chain 800.

In another example of the operation of the signal chain 800, thespectral noise density of the conditioning circuit increases whilesignal conditioning circuit 805 is operated in the low bandwidthconfiguration (e.g., a lower power configuration). The conditioningcircuit 805 compensates for the higher spectral noise density byenabling additional internal analog filtering of an input signal, suchas the input signal 168. The converter circuit 810 may provide furthercompensation by capturing oversampling the output of the signalconditioning circuit 805 and by enabling apply digital filtering of thecaptured samples. This may result in reduced power consumption in theconditioning circuit power, but increased power consumption in theconverter circuit 810, such as due to the additional samples capturedand used facilitate the digital filtering. The converter circuit 810 isconfigured, or configurable, to obtain a target balance, or trade-off,between the reduced power consumption of the signal conditioning circuit805 and the increased power consumption of the converter circuit. In anexample, the converter circuit 810 is configured to obtain the targetbalance by through synchronization of its internal settling timers withthe settling time of the signal conditioning circuit 805, and throughcontrol of over-sample ratios for converter circuit's digital filtersand the conditioning circuit's bandwidth configuration.

The described modifications or improvements of the signal conditioningcircuit 805 or the converter circuit 810 can be incorporated in any ofthe signal chains described herein.

FIG. 8B illustrates an example of electronic signals associated withoperation of a signal chain having embedded power management integratedin a data converter circuit and signal conditioning circuit having aselectable bandwidth. In an example, FIG. 8B illustrate signals that aregenerated by one or more components of the signal chain 800 duringoperation. As shown in FIG. 8B, BW signal 820 is an example of thecontrol signal 815, driven by the converter circuit 810 to configure thesignal conditioning circuit 805 to a high bandwidth mode during power-up184 and power down 825, as described herein. In an example, the controlsignal 815 is actuated (e.g., driven high or low) at a time T2′ afterthe sensor circuit 105 is enabled and settled after a power cycling. Theremaining signal are indicative of operations of the signal chain 800that correspond to operations of the signal chain 100, as described inthe discussion of FIG. 1B.

VARIOUS EXAMPLES

Example 1 is a system for processing a signal in a signal chain havingdecentralized embedded power management of components of the signalchain, the system comprising: an input circuit to generate a measurementsignal responsive to a stimulus, the measurement signal indicative of acharacteristic of the stimulus; and a signal converter circuit coupledto the input circuit to convert the measurement signal to a digitalsignal according to a timing condition for capturing a sample of themeasurement signal, the signal converter comprising: a control circuitto provide electrical power to the input circuit based on the timingcondition; and a sampling circuit to capture the sample of themeasurement signal responsive to an indicator signal generated by thesensor circuit.

In Example 2, the subject matter of Example 1 includes, wherein theinput circuit comprises a conditioning circuit that is configured tocondition an output signal obtained from a sensor circuit to generatethe measurement signal, the control circuit is configured to provideelectrical power to the conditioning circuit according to the timingcondition.

In Example 3, the subject matter of Example 2 includes, wherein theconditioning circuit is configured to provide electrical power to thesensor circuit responsive to a timing condition of the conditioningcircuit.

In Example 4, the subject matter of Examples 1-3 includes, wherein theinput circuit comprises a sensor circuit that is configured to generatethe measurement signal, the control circuit is configured to interfacewith a sensor device to provide an output signal to generate themeasurement signal.

In Example 5, the subject matter of Example 4 includes, wherein thecontrol circuit provides electrical power the sensor circuit accordingto the timing condition.

In Example 6, the subject matter of Examples 1-5 includes, wherein thecontrol circuit is configured to power-off the signal converter circuitresponsive to providing power to the input circuit.

In Example 7, the subject matter of Examples 1-6 includes, wherein thecontrol circuit is configured to, responsive to receiving the adjustedmeasurement signal from the conditioning circuit, power-on the signalconverter circuit and capture the sample of the measurement signal.

In Example 8, the subject matter of Examples 1-7 includes, whereinmeasurement signal comprises a first signal having a first polarity andsecond signal having a second polarity, the system further comprising: afirst switching circuit controllable by the conversion circuit to switchthe first signal and the second signal between a first input and asecond input of the signal converter circuit.

In Example 9, the subject matter of Example 8 includes, wherein theinput circuit that is configured to condition an output signal isobtained from a sensor circuit to generate the measurement signal, andthe first switching circuit is coupled to one or more inputs of theconditioning circuit.

In Example 10, the subject matter of Examples 8-9 includes, wherein theinput circuit comprises a sensor circuit that is configured to generatethe measurement signal, and the first switching circuit is coupled tofirst and second power terminals of the sensor circuit.

In Example 11, the subject matter of Examples 8-10 includes, the signalconverter circuit further comprising a second switching circuitcontrollable by the conversion circuit to switch the first input and asecond input of converter circuit to corresponding first input andsecond inputs of the sampling circuit.

In Example 12, the subject matter of Examples 1-11 includes, wherein thetiming condition comprises a settling time of the measurement signal atthe input of the signal converter circuit.

Example 13 is a system for processing a signal in a signal chain havingdecentralized embedded power management of components of the signalchain, the system comprising: a sensor circuit to generate a measurementsignal that is indicative of a physical quantity; a conditioning circuitcoupled to an output of the sensor circuit to provide an adjustedmeasurement signal according to an input circuit criterion; and aconversion circuit coupled to the conditioning circuit to convert asample of the adjusted measurement signal to a digital signal, theconversion circuit comprising: a first control circuit to provide acontrol signal to power-on the conditioning circuit and to power-off theconversion circuit responsive to providing control signal to theconditioning circuit; and a second control circuit to power-on theconversion circuit responsive to the conditioning circuit providing theadjusted measurement.

In Example 14, the subject matter of Example 13 includes, wherein theconversion circuit comprises a third control circuit to provide a secondcontrol signal to selectively configure the conditioning circuit to havea first signal bandwidth or a second signal bandwidth.

In Example 15, the subject matter of Examples 13-14 includes, whereinthe first control circuit is configured to provide the control signal topower-on the sensor.

In Example 16, the subject matter of Examples 13-15 includes, whereinthe system further comprises: a commuter circuit comprising: an inputcoupled to an output of the sensor circuit to receive the measurementsignal; an output coupled to the input of conditioning circuit toprovide the measurement signal to the conditioning circuit; and whereinthe conversion circuit comprises a third control circuit to actuate thecommutator circuit to determine an electrical path of a first and secondsample of the measurement signal through the conditioning circuit.

In Example 17, the subject matter of Example 16 includes, wherein thesystem further comprises an analog summation circuit to combine thefirst and second sample of the measurement signal to remove reduce asignal offset in the first and second sample.

In Example 18, the subject matter of Examples 16-17 includes, whereinthe system further comprises a digital summation circuit to combine thefirst and second sample of the measurement signal to remove reduce asignal offset in the first and second sample.

Example 19 is a method of operating a signal chain having decentralizedembedded power management of components, the method comprising:providing a first control signal from the signal converter circuit to asignal conditioning circuit, the first control signal providing power tothe signal conditioning circuit to generate a measurement signal;powering off the signal converter circuit responsive to proving thefirst control signal; obtaining a second control signal from the signalconditioning circuit responsive to the signal conditioning circuitgenerating the measurement signal; and powering on the signal convertercircuit and obtaining a sample of the measurement signal responsive toreceiving the second control signal.

In Example 20, the subject matter of Example 19 includes, powering-offthe signal conditioning circuit responsive to obtaining the sample ofthe measurement signal.

Example 21 is at least one machine-readable medium includinginstructions that, when executed by processing circuitry, cause theprocessing circuitry to perform operations to implement of any ofExamples 1-20.

Example 22 is an apparatus comprising means to implement of any ofExamples 1-20.

Example 23 is a system to implement of any of Examples 1-20.

Example 24 is a method to implement of any of Examples 1-20.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred togenerally as “examples.” Such examples can include components inaddition to those shown or described. However, the present inventorsalso contemplate examples in which only those components shown ordescribed are provided. Moreover, the present inventors also contemplateexamples using any combination or permutation of those components shownor described (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein. In the event of inconsistent usages between this document andany documents so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes componentsin addition to those listed after such a term in a claim are stilldeemed to fall within the scope of that claim. Moreover, in thefollowing claims, the terms “first,” “second,” and “third,” etc. areused merely as labels, and are not intended to impose numericalrequirements on their objects.

Method examples described herein can be machine or computer-implementedat least in part. Some examples can include a computer-readable mediumor machine-readable medium encoded with instructions operable toconfigure an electronic device to perform methods as described in theabove examples. An implementation of such methods can include code, suchas microcode, assembly language code, a higher-level language code, orthe like. Such code can include computer readable instructions forperforming various methods. The code may form portions of computerprogram products. Further, in an example, the code can be tangiblystored on one or more volatile, non-transitory, or non-volatile tangiblecomputer-readable media, such as during execution or at other times.Examples of these tangible computer-readable media can include, but arenot limited to, hard disks, removable magnetic disks, removable opticaldisks (e.g., compact disks and digital video disks), magnetic cassettes,memory cards or sticks, random access memories (RAMs), read onlymemories (ROMs), and the like.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

The claimed invention is:
 1. A system for processing a signal in a signal chain having decentralized embedded power management of components of the signal chain, the system comprising: an input circuit to generate a measurement signal responsive to a stimulus, the measurement signal indicative of a characteristic of the stimulus; and a signal converter circuit coupled to the input circuit to convert the measurement signal to a digital signal according to a timing condition for capturing a sample of the measurement signal, the signal converter comprising: a control circuit to provide electrical power to the input circuit based on the timing condition; and a sampling circuit to capture the sample of the measurement signal responsive to an indicator signal generated by the sensor circuit.
 2. The system of claim 1, wherein the input circuit comprises a conditioning circuit that is configured to condition an output signal obtained from a sensor circuit to generate the measurement signal, the control circuit is configured to provide electrical power to the conditioning circuit according to the timing condition.
 3. The system of claim 2, wherein the conditioning circuit is configured to provide electrical power to the sensor circuit responsive to a timing condition of the conditioning circuit.
 4. The system of claim 1, wherein the input circuit comprises a sensor circuit that is configured to generate the measurement signal, the control circuit is configured to interface with a sensor device to provide an output signal to generate the measurement signal.
 5. The system of claim 4, wherein the control circuit provides electrical power the sensor circuit according to the timing condition.
 6. The system of claim 1, wherein the control circuit is configured to power-off the signal converter circuit responsive to providing power to the input circuit.
 7. The system of claim 1, wherein the control circuit is configured to, responsive to receiving the adjusted measurement signal from the conditioning circuit, power-on the signal converter circuit and capture the sample of the measurement signal.
 8. The system of claim 1, wherein measurement signal comprises a first signal having a first polarity and second signal having a second polarity, the system further comprising: a first switching circuit controllable by the conversion circuit to switch the first signal and the second signal between a first input and a second input of the signal converter circuit.
 9. The system of claim 8, wherein the input circuit that is configured to condition an output signal is obtained from a sensor circuit to generate the measurement signal, and the first switching circuit is coupled to one or more inputs of the conditioning circuit.
 10. The system of claim 8, wherein the input circuit comprises a sensor circuit that is configured to generate the measurement signal, and the first switching circuit is coupled to first and second power terminals of the sensor circuit.
 11. The system of claim 8, the signal converter circuit further comprising a second switching circuit controllable by the conversion circuit to switch the first input and a second input of converter circuit to corresponding first input and second inputs of the sampling circuit.
 12. The system of claim 1, wherein the timing condition comprises a settling time of the measurement signal at the input of the signal converter circuit.
 13. A system for processing a signal in a signal chain having decentralized embedded power management of components of the signal chain, the system comprising: a sensor circuit to generate a measurement signal that is indicative of a physical quantity; a conditioning circuit coupled to an output of the sensor circuit to provide an adjusted measurement signal according to an input circuit criterion; and a conversion circuit coupled to the conditioning circuit to convert a sample of the adjusted measurement signal to a digital signal, the conversion circuit comprising: a first control circuit to provide a control signal to power-on the conditioning circuit and to power-off the conversion circuit responsive to providing control signal to the conditioning circuit; and a second control circuit to power-on the conversion circuit responsive to the conditioning circuit providing the adjusted measurement.
 14. The system of claim 13, wherein the conversion circuit comprises a third control circuit to provide a second control signal to selectively configure the conditioning circuit to have a first signal bandwidth or a second signal bandwidth.
 15. The system of claim 13, wherein the first control circuit is configured to provide the control signal to power-on the sensor.
 16. The system of claim 13, wherein the system further comprises: a commuter circuit comprising: an input coupled to an output of the sensor circuit to receive the measurement signal; and an output coupled to the input of conditioning circuit to provide the measurement signal to the conditioning circuit; and wherein the conversion circuit comprises a third control circuit to actuate the commutator circuit to determine an electrical path of a first and second sample of the measurement signal through the conditioning circuit.
 17. The system of claim 16, wherein the system further comprises an analog summation circuit to combine the first and second sample of the measurement signal to remove reduce a signal offset in the first and second sample.
 18. The system of claim 16, wherein the system further comprises a digital summation circuit to combine the first and second sample of the measurement signal to remove reduce a signal offset in the first and second sample.
 19. A method of operating a signal chain having decentralized embedded power management of components, the method comprising: providing a first control signal from the signal converter circuit to a signal conditioning circuit, the first control signal providing power to the signal conditioning circuit to generate a measurement signal; powering off the signal converter circuit responsive to proving the first control signal; obtaining a second control signal from the signal conditioning circuit responsive to the signal conditioning circuit generating the measurement signal; and powering on the signal converter circuit and obtaining a sample of the measurement signal responsive to receiving the second control signal.
 20. The method of claim 19, further comprising powering-off the signal conditioning circuit responsive to obtaining the sample of the measurement signal. 